This is the conclusion to 47 year old male: Holiday Indigestion. Thanks go to a long time reader Nicholas Eisele for this holiday case! Editor's Note: sorry for the delay, it helps to press "publish"!

When we left off, our patient was in the back of the truck with a burning sensation radiating to his back. We had run a 12-Lead ECG and our partner was wondering which facility you wanted him to drive to.

To answer that question, we should look at the 12-lead!

This 12-Lead shows a normal sinus rhythm at 70 bpm without ectopy or bundle branch block. A case could be made for incomplete right bundle branch block given a QRSd of ~110ms. Strikingly we have ST-depression in I, aVL, and V1-V5 with ST-elevation in lead III. Anytime you see flat or downsloping ST-depression in aVL you should look for elevation in the inferior leads (typically III). When present, it is almost certainly an inferior wall MI.

Many readers commented that the ST-depression in V1-V5 could be either a sign of a posterior wall MI or a "anterior ischemia". It is important to remember that ST-depression from ischemia does not localize! This concept is so important, I'm going to list it again:

Traditional evaluation of ST-depression has taught that focal ischemia may cause localized ST-depression, however, this is not the case. Subendocardial ischemia causes diffuse ST-depression and will not be found in a localized pattern. Any time you have localized ST-depression you must consider it to be a reciprocal change first!

In our case, we have ST-elevation in lead III which clinches the diagnosis of an inferior wall myocardial infarction with possible posterior extension. A subsequent ECG revealed evolving ST-elevation in the inferior leads:

The paramedics in this case recognized this fact, activated a STEMI alert, and transported the patient to their nearest PCI center. The in-hospital ECG showed continued evolution of the IWMI with the most impressive elevation and depression of the patient's clinical course:

They achieved an impressive 83 minute first medical contact to balloon time with one stent placed in the RCA.

We hope you've enjoyed this case as much as we did, but more importantly this case presents some great teaching points:

Sometimes STEMI patients will have atypical symptoms.

A single ECG is not enough to detect all STEMI patients, serial 12-Lead ECG's should be acquired on all patients who receive one.

ST-depression from ischemia does not localize, localized ST-depression should be considered a reciprocal change until proven otherwise.

5 Comments

Quick question Christopher and I thought I'd ask here so others can see, how do I get my monitor to print off the computer measured J point readings with my 12-lead like that? I work in two services, one with LP12 and one with LP15.

The LP12 I do not believe can be configured to print the J-point measurements. As for the LP15, I thought printing of STJ measurements was the default and I cannot find any configuration options to the contrary. Although, interestingly enough, I have a 2008 version of the LP15 manual which does not include STJ measurements, which when compared to the 2010 version of the LP15 manual shows the addition of the STJ measurements.

My guess is you have an older version of the software on your LP15's. I'm going to get ahold of my contacts at Physio-Control and find out for you!

Brooks Walsh MDComputer misses it, but the medic catches it.Well this blog is a great place to start! We cover most every aspect of emergency electrocardiography, with a variety of authors, and multiple perspectives, usually in a clinical context. If it is a book you are looking for, I prefer Ken Grauer's. I started with Dr Grauer as a paramedic student and I still…
2015-07-27 01:45:18